David Steiner was a Starfleet pilot in the 24th century.
While in Starfleet, he was the night watch conn officer aboard the USS Rutledge. At some point after the end of the Dominion War, he left Starfleet and flew ships along trade routes that brought in money (particularly from Bajor to Earth).
In 2386 he was interviewed by Jake Sisko in Quark's Bar, Grill, Gaming House, Holosuite Arcade, Gift Shop and Ferengi Embassy aboard Deep Space 9. In it he discussed his life, and most notably, the events surrounding the Klingon Empire's conquering of Gila IV. (ST website : The Path to 2409)